This Hub City PB251UR series pillow block has a cast iron housing with a high shaft height and two bolt holes and a set screw locking collar. The cast iron housing is rigid and dampens vibration and its two bolt holes provide mounting stability. A collar extends from the bearing inside ring to lock the collar and bearing onto the shaft with two set screws spaced 120 degrees apart for a three-point contact hold. The steel single-row, deep groove ball bearing insert is self-aligning and accommodates misalignments between the shaft and the housing. A pressed steel cage spaces the rollers for even load distribution and prevents contact to reduce friction, vibration, and noise. Nitrile rubber seals with steel guards on both sides of the bearing protect against contaminants and retain lubricant applied at manufacture and the bearing housing has a grease fitting for reapplying lubricant. Pillow block units are suitable for use in industrial and commercial applications including conveyors, fans and blowers, construction machinery, and processing equipment.

Mounted bearings combine a bearing mounted inside a housing unit. The bearing housing replaces the need for a casting or weldment to position the bearing securely for reliable operation, and its design determines the type of insert bearing. Insert bearings use rolling elements (ball, cylindrical, spherical, barrel, needle, spindled, or tapered) to maintain the separation between moving parts to reduce rotational friction, and to support radial and axial loads. Available in a variety of materials and mounting configurations, mounted bearings can be one- or two-piece, they can have an extended inner ring and locking device, and they can have seals and end caps that retain lubrication and protect the working parts of the bearing from environmental debris. Mounted bearings support shafts in a variety of mounting configurations (flange block, hanger, pillow block, and take-up block), and are used in a range of applications from light duty shaft guidance on conveyors to road building equipment and crushers.

Hub City manufactures power transmission products for use in transportation, packaging, construction, material handling, and medical and food processing equipment. The company, founded in 1892, is a subdivision of Regal-Beloit and headquartered in Beloit, WI.